is more than a bird can do in the air. Nay further, that men dwell there, and build large palaces; and that they have so quick a method of travelling, that they can, without any trouble, remove their whole families and houses into the most distant countries. A person, I say, such as this, continues Galilæo, would never think of the ocean of fishes, of ships, and fleets. So in the moon, there may exist some beings, who having no resemblance to us, can in no wise enter into our thoughts.

This reasoning is pure, and is stamped with the integrity of unpresuming genius. But although we acquiesce in the supposition that the planets are inhabited, is it not difficult, it will be said, to conceive how the comets can be peopled, which pass from the extremity of heat to the extremity of cold? The comet which appeared in 1759, and which returned the quickest of any that we have an account,* had a winter of 70 years. As to its heat, this surpassed imagination. With us, a body is susceptible of only a certain degree of heat, Iron made red, and still continued in a violent fire, only vitrifies and turns to cinder. If therefore, the comet of 1680, according to Newton,

was

!

1

was two thousand times hotter than red hot iron, its composition must be totally different from that of any substance known to man. And yet, can it be conceived that such mighty masses should be formed for nothing? Where, I repeat, is the necessity that all living beings should be like us? Is it not more reasonable to suppose, that different organizations, different forms, are calculated for different worlds? To suppose otherwise, is it not to adopt the prejudice which led the ancients to deny, that the torrid and the frigid zones were habitable? Even the pure element of fire, for ought we know to the contrary, may have its population, may have its appropriate inhabitants. But, indeed, we are lost, when we attempt to reflect upon this extraordinary class of the planets. For instance, the comet which appeared from the 22d December, 1680, to the 18th of March, 1681, had then appeared only four times. The first, in the September which followed the death of Julius Cæsar, forty three years before Christ. The second, in the 531st year of Christ. The third, in the year of Christ 1106. And the fourth, in the year 1680. What a prodigious period, in the performance of its revolutions!

These wandering planets, little as we think of them in general, are yet of greater moment perhaps in the scale of creation, than either we ourselves, or any of the few other globes that have been discovered to appertain to the solar system. Their numbers, indeed, are alone sufficient to indicate their importance. They greatly exceed the planets. The precise number of those belonging to our system is unknown, It is said, that more than four hundred and fifty had been seen previous to 1771. Those, however, whose orbits have been sufficiently and accurately settled, so as that we can ascertain their identity when they shall appear again, amount to about fifty nine, reckoning as late as the year 1781.* But there yet may be thousands. How glorious then to form an idea of these travelling worlds, peopled as it were with observers, employed in the contemplation of the universe at large, as we are in the contemplation of an insignificant atom of it: passing from one sun to another: observing the orbits of the celestial spheres: viewing their particular, as well as their general revolutions: over their heads, thousands of years rolling, merely as thousands of days over ours. But the

the flight is too sublime for circumscribed capa-
cities. It is enough, that if as on our little
earth, we can trace the works of a bounteous
Providence, so we can in the heavens grasp in
demonstration, the wonders of his omnipo-

tence,
Can a blind fatality have originated
such harmony; or could effects so transcendant.
have proceeded from non-intelligence and ne-
cessity? Miserable absurdity, humiliating in-
stance of imbecility and ingratitude!

LETTER LETTER XLIX.

ASTRONOMY is said to have been the daughter of idleness; as geometry was of interest; and poetry of love. But the assertion is not well grounded. Astronomy is not merely a speculative science: its use is as extensive as its researches are profound. To it, navigation owes its safety; to it, commerce is indebted for its extension; and geography for its improvement. But, what above all, speaks its praise, is, that it has led the way to the diffusion of knowledge, and to the civilization of mankind. Thus then we may be allowed to consider the science of astronomy as the most sublime, the most interesting, and the most useful, that has at any time employed the faculties or engaged the attention of man. How high it lifts the mind above the low, contracted prejudices of the vulgar; how clearly does it convince the understanding; and how indelibly stamp the conviction of the existence, the wisdom, the goodness, and the superintendancy of a Supreme Being! Can any thing, therefore, raise the glory of the human species